Multiple electric plug receptacle



Sept. 29, 1953 LANCELOT 2,654,074

MULTIPLE ELECTRIC PLUG RECEPTACLE Filed Oct. 7, 1950 INVENTOR. Daniel Lancelot.

, ATTORNEY Patented Sept. 29, 1 953 UNITED STATES PATENT OFFICE 4 Claims.

This invention relates generally to electrical plug receptacles and more in particular to a plug receptacle which may be plugged into a standard flush mounted plug receptacle forming a permanent part of the wiring of a building.

Numerous variations of plug-in types of plug receptacles are available for multiplying plug-in facilities at a particular plug receptacle. In most of these, the plug-in receptacle comprises a housing of electrical insulating material having plug receptacles, in several of the faces thereof, connected to a pair of protruding prongs adapted to plug into a standard flush mounted receptacle. Usually three, and sometimes more, plug receptacles are provided in the faces of the plug-in unit. Thus the facilities of a single outlet, by such an expedient, are increased at least three fold. Thus a concentration, for example, of household electrical devices such as appliances and portable lighting units may be conveniently handled.

The mechanics of such an arrangement however, are poor. The entire mechanical load hangs on the prongs of the plug-in plug receptacle and after a short period of time, mechanical failure of the flush mounted plug receptacle occurs. ,Since this last-named receptacle is essentially, a permanent part of the wiring system, its replacement is a matter of some consequence. Plug-in receptacles of this type, therefore, do not represent an adequate solution to the problem.

One object of this invention is to provide a plug-in type of plug receptacle which may be securely mechanically attached to a standard flush mounted lug receptacle forming a permanent part of a wiring system.

More in particular it is an object of this invention to provide a plug-in type of plug receptacle having two pairs of plug connectors for plug-in connection with a standard double plug receptacle of the flush mounted type wherein provision is had for securely mechanically attaching the plug-in plug receptacle to the standard plug receptacle.

It is also an object of this invention to provide plug-in plug receptacles of the character referred to in the preceding objects with a plurality of plug receptacles therein.

The foregoing statements are merely illustrative of the various aims and objects of this invention. Other objects and advantages will become apparent upon a study of the following-disclosure when considered in conjunction with the accompanying drawing, in which:

Fig. 1 is a plan view of a plug-in type of plug receptacle embodying the principles of this invention;

Fig. 2 is a longitudinal sectional view of the plug-in plug receptacle of Fig. 1;

Fig. 3 is a bottom plan view of the plug-in plug receptacle of Fig. 1; and

Figs. 4, 5 and 6 are, respectively, sectional views taken on the lines IV-IV, VV and VI-VI, respectively, of Fig. 2.

The several illustrations of the drawing illustrate a preferred embodiment of this invention designed for plug-in connection to a standard double flush mounted plug receptacle of the type permanently wired into a wiring system. These standard plug receptacles are usually placed in a wall of a building, in keeping with the electrical code, and are mounted in metal boxes, secured to the building frame in such a position that the edges defining the open end of the box are substantially at the finished surface of the wall. Such a box is not shown in the interest of simlicity. The standard plug receptacle is fitted into the box and secured thereto by means of screws (not shown). In the case of a double plug receptacle, as l (or duplex convenience outlet as it is sometimes known), when mounted in the box, each plug receptacle face 2 protrudes about one-eighth of an inch beyond the wall surface. A cover plate 3 of rectangular planforming having a pair of openings therein neatly fitting about the edges of the faces of the plug receptacles covers the box opening and seats against the wall. In practice, a cover plate mounting screw clears through the cover plate and threads into a threaded hole in the plug receptacle between the plug receptacle faces to secure the cover plate in position. Alternatively some standard receptacles may require the use:

of two screws in mounting the cover plate.

The present invention contemplates establish-- ing electrical connections in the two plug receptacles of a standard double plug receptacle, for a. plurality of plug receptacles in a single insulating block and securing'the assembly in position by a. screw or screws as required clearing through the plug receptacle block and threadedly engaging the threaded hole in the standard double plug receptacle.

In Figs. 1, 2 and 3, the insulating receptacle base or housing is designated 5 and is provided with four plug receptacles 6a, 6b, 6c and 6d which are grouped in pairs on opposite sides of alongitudinal center line through the base. In Fig. 1, the position of the standard double plug receptacle is indicated by the individual plug receptacle 2', in dotted outline, and the position of the standard receptacle cover plate 3 is also indicated in dotted outline. As will be seen from the bottom view of Fig. 3, the plug-in type of plug receptacle of this invention is provided with two pairs of plug prongs la, lb and 8a, 8b, respectively, which are suitably spaced along the base in correspondence with the spacing of the prong receiving openings 9 01' the standard double plug receptacle I.

Th prongs 1a, 1b, 8a and 8b may be an integral part of, or otherwise suitably joined to, a plurality of current carrying strips secured in suitable cavities in the insulating basc 5 to prgvide circuit connections to the respective plug receptacles 6a through 6d. To this end, prong la is integrally formed with strip (c which egtends between the prong-receiving openings and H of the plug receptacles 6c and 611, respectively. Prong 1b is an integral part of a u-shaped metal strip 1d, being forme a t t e o he shed l t ereaf- The bi'glit of the U-shaped strip 1d extends P h Pl? 1? 1 W8 li 0 h U-shaped member straddles the prpngerepeiyin op n n nd '1 9f P 45 re eptacl an respectively. Contact strips io and if, which may b an te ra Part o shi s 7!; an 1d. r spe P ec u wardl hi epehin s an I2 adjacent one side thereof (see Fig. 5 to slids ly e a the pr s a sthh rd plu fi to u ed WQ'QP- l reh e vins openings II and I; have similar contact strips (not shown), integrally formed with strips 1,0 and 1 fitted her i s t9 eh? Pd renewedn r e t el to t i and r t r l formed h r n eh and ea h is p evided with contact strips projecting into pron receiving openings [15; i6 and 11. Contact strips Be and 8/ which are integrally iorrned with strips 8c and 8d are shown in Fig. 5 intheir respective p it on in r h -ree i ih lfi l gs, U and 1.6 .of plug receptacle ta. [lihis construction whhecis 151118" e ta les W hd B i pa ll and connects. P 4 9 P 5 @41 W i P ale ub i t e P us re ept l ca acity of th standard double plug receptacle 1.

As earlier cf the strips [0, 1d and 8c, 8d are disposed in suitable cavities in the base or housing.. $uitable means for securing these strips in the base is represented in the mounting'tabs l8 integrally formed with the re,- p iv strips secured to the base by screws f9 which clear therethrough and threaded-1y enge the base. The details of this mounting ap: pear in Figs. 3 and 6. bottom of this plug-in yp of P u receptacle is covered with a sheet of material of electrical insulating material 29 (not shown in 3) to insnlatedly enclose the metal strips Ic, 1d, 8c and go. la, 1b, 8a .and 81) project through suitable openings in this sheet 20. In the illustrated embodiment a marginal skirt 2| is provided, the bottom edges of which engage the finished wall surface and space the unit a suflicient distance from the wall surface to clear the faces of plug receptacles 2 .of the standard double plug receptacle. The unit is securely mounted .to the standard plug receptacle 4 by a screw 22 which clears through the insulatin base o ow 5 has t mhslsh h thr hd ho1e in standard plug rcqeptacle l which normally rev ceives the cover plate screw. affording a strong mechanical connection completely relieuing the prongs in the plug receptacle in through 5d of mechanical load.

Whi e We Pa e 9; 19. 5 r qe a les have been 4 illustrated, it will be appreciated that the parallel connections may be extended to include any number of plug receptacles within practical limits. Although the present design has been made to straddle the cover plate 3 for the standard receptacle I so that the cover plate need not be removed, it will be appreciated that other designs may be made which are exactly the size of the standard double receptacle cover plate, removal of the cover plate being optional. In any event. the unit is preferably of such a size as to completely cover the standard receptacle and its mounting box as does the standard cover plate.

It will be appreciated that numerous variations in -design details with regard to the configuration of parts'ahd the location of the plug receptacles oi plugein fixture may be had without departing from the spirit and scope of this invention. Accordingly, it is intended that the foregoing disclosure and the illustrations of the drawings shall be considered only as illustrative 9 h? m l-9. .9 6 h t en nc aim:

1. An electrical convenience outlet unit for attachment to a standard builtfin, flush mounted, convenience outlet having two conventional plug receptacles and at least one threaded hole for receiving a cover plate mounting screw, comprising, in combination, a base of electrical insulating material, o pairs of m tal bayon t p n s fitted and secured in said base in positions to plug into the two onventional p u recep cl s, resp ctiveiy; a metal strip connected to one prong of one of said pairs of pron s and secured in said base, a second metal strip corresponding to the first-mentioned metal strip secured to a prong .of the other pair of prongs positioned diagonally opposite said first mentioned prong, said second metal strip being secured in said base in a position substantially paralleling and opposite to said first-mentioned metal strip, metal strips connected to the remaining prong of each pair of prongs and secured in said base in parallel spaced relation with the metal strip connected to the other prong of that pair forming spaced pairs of metal strips, said base having spaced pairs of openings therethrough into said spaced pairs of metal strips for permitting the entrance ofthe prongs ,of standard electrical plugs into enagement-with the respective pairs-of metal strips, whereby a plurality of parallel connections is atforded with each pair of metal strips, and a mount g screw clearing through said base and adapted to engage the threaded hole in the standard convenience .outletto secure said base over the standard convenience outlet.

2. electrical convenience outlet .unit for attachrnent to a standard built-in, flush mounted, convenience outlet having two conventional plug receptacles and at least one threaded hole for receiving a'cover plate mounting screw, comprising, in combination, a base of electrical insulating material, two pairs .of metal bayonet prongs fitted and secured in said base in positions to plug into the two conventional plug receptacles, respectively; a metal strip connected to one prong of one of said pairs of .prongs and secured in said base, a second metal strip corresponding to the first-mentioned metal strip secured to a prong of the other pair of prongs located in a position diagonally opposite said first-mentioned prong, said second metal strip being secured in said base in a position substantially parallelling and opposite to said first-mentioned meal strip, m al strips connected to the remaining prong of each pair of prongs and secured in said base in parallel spaced relation with the metal strip connected to the other prong of 'that pair forming spaced pairs of metal strips, said base having spaced pairs of openings therethrough into said spaced pairs of metal strip for permitting the entrance of the prongs of standard electrical plugs into engagement with the respective pairs of metal strips, whereby a plurality of parallel connections is aiTorded with each pair of metal strips, and a mounting screw clearing through said base and adapted to engage the threaded hole in the standard convenience outlet to secure said base over said standard convenience outlet, said base including a portion having marginal edges sufficient to completely cover the standard convenience outlet.

3. An electrical convenience outlet unit for attachment to a standard built-in, flush mounted, convenience outlet having two conventional plug receptacles and at least one threaded hole for receiving a cover plate mounting screw, comprising, in combination, a base of electrical insulating material, two pairs of metal bayonet prongs fitted and secured in said base in positions to plug into the two conventional plug receptacles, respectively; a metal strip connected to one prong of one of said pairs of prongs and secured in said base, a second metal strip corresponding to the first-mentioned metal strip secured to a prong of the other pair of prongs located in a position diagonally opposite said first-mentioned prong, a first U-shaped metal strip having a long leg and a short leg, said short leg being connected adjacent its extremity of the remaining prong of said one pair of prongs and the long leg thereof being secured in said base in a position parallelling and spaced from. the first-mentioned metal strip forming one pair of spaced metal strips, a second U-shaped metal strip having a long leg and a short leg, the short leg of the second U-shaped metal strip being connected to the remaining prong of the other pair of metal prongs and the long leg thereof being secured in said base in a position parallelling and spaced from said second metal strip forming a second pair of spaced metal strips, said base having spaced pairs of openings into said spaced pairs of metal strips for permitting the entrance of the prongs of standard electrical plugs into engagement with the respective pairs of spaced metal strips whereby a pluralit of parallel connections are afforded with each pair of metal strips, and a mounting screw clearing through said base and adapted to engage the threaded hole in the standard convenience outlet to secure said base over the standard convenience outlet.

4. An electrical convenience outlet unit for attachment to a standard built-in, flush mounted, convenience outlet, having two conventional plug receptacles and at least one threaded hole for receiving a cover plate mounting screw, comprising, in combination, a base of electrical insulating material, two pairs of metal bayonet prongs fitted and secured in said base in positions to plug into the two conventional plug receptacles, respectively; a metal strip connected to one prong of one of said pairs of prongs and secured in said. base, a second metal strip corresponding to the first-mentioned metal strip secured to a prong of the other pair of prongs located in a position diagonally opposite said first mentioned prong, a first U-shaped metal strip having a long leg and a short leg, said short leg being connected adjacent its extremity to the remaining prong of said one pair of prongs and the long leg thereof being secured in said base in a position paralleling and spaced from the first-mentioned metal strip forming one pair of spaced metal strips, a second U-shaped metal strip having a long leg and a short leg, the short leg of the second U-shaped metal strip being connected to the remaining prong of the other pair of metal prongs and the long log thereof being secured in said base in a position paralleling and spaced from said second metal strip forming a second pair of spaced metal strips, said base having spaced pairs of openings into said spaced pairs of metal strips for permitting the entrance of the prongs of standard electrical plugs into engagement with the respective pairs of metal strips whereby a plurality of parallel connections is afforded with each pair of metal strips, and a mounting screw clearing through said base and adapted to engage the threaded hole in the standard convenience outlet to secure said base over the standard convenience outlet, said base including a portion having marginal edges sufficient to completely cover the standard convenience outlet,

DANIEL LANCELOT.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,717,836 Conner June 18, 1929 2,299,617 Eisenberg Oct. 20, 1942 2,454,024 Alemaghides Nov. 16, 1948 2,462,756 Leopold Feb. 22, 1949 2,489,741 Bonham Nov. 29, 1949 

